Tanks and Weights

[WaterFox]

New diver here and I'm trying different equipment setups before I decide which gear I want.

For my dives I've been using AL63's because that's what the instructor put me in for my open water class. I'm going to rent an AL80 just to see how I like it before I make any tank purchases.

My question is would I need more or less weight when switching from 63's to 80's. I was thinking less because it is a bigger tank and thus heavier. But then I was also thinking less because it is more positively buoyant when empty. What is the real answer?

Thanks.

 

[TSandM]

According to the cylinder spec chart at TDL, Al63s are +2.6 lbs when empty, Al80's are +4.4. So you need about two pounds MORE weight to dive the 80's in comparison with the 63s.